Subjects are invited to take part in this research study because they have soft tissue sarcoma. The purpose of this study is to give chemotherapy in two different doses (high dose & standard dose) and to compare (at the end of 12 months) which dose of chemotherapy will better eliminate the sarcoma or prevent it from recurring. This study will also compare the side effects of the two doses. The study will consist of two groups:Patients with sarcomas that have spread and cannot be surgically removed; and Patients who have locally contained sarcomas that have been removed by surgery. Before subjects enter this study, they will undergo or have previously undergone a biopsy (removal of tissue) or have had a surgical procedure to remove their cancer. Subjects will be given doxorubicin in a solution through one of their veins continuously for three days. Subjects will be randomly assigned (a process similar to the tossing of a coin) to receive one of two different doses of ifosfamide. Subjects will receive your assigned dose of ifosfamide by vein over 1 to 2 hours for four days. Mesna will be given with the ifosfamide, which will be continued through the fourth day of treatment to protect the bladder. This will be continued for a total of six cycles if the subjects' cancer is not surgically removable. If the cancer (sarcoma) has already been surgically removed, subjects will receive only four cycles of chemotherapy. Likewise, if subjects are to receive chemotherapy before having the cancer (sarcoma) removed, subjects will receive four cycles of chemotherapy; and once subjects have recovered from chemotherapy, their cancer will be surgically removed. Following the completion of the surgical and/or chemotherapy treatment, subjects may undergo radiation therapy. Subjects will be given G-CSF to reduce the side effects of the drugs on their white blood cells. G-CSF is given daily, as a shot immediately beneath the skin. Before the administration of chemotherapy, subjects will undergo an erythromycin breath test, whereby they will be given a special form of erythromycin into a vein and then be asked to breathe into a special machine. This breath test will help us determine how well the body will eliminate the chemotherapy from the body. Routine laboratory tests (including blood and urine) and x-rays will be done during subjects' treatment so the doctor can check their body's response to treatment. We will also draw blood specimens and collect urine samples to determine how the body is breaking down the ifosfamide and eliminating it. There will be 17 samples of blood/urine drawn.